What is the PSB Thumb Brace? The PSB Thumb Brace is designed to limit movements away from the index finger which can cause damage to the capsule enclosing the thumb joint. Typically trauma may be caused by a fall, stumble or collision with the excessive force pushing the thumb backwards or sideways causing injury. A common occurrence in skiing & ball sports such as football, rugby, netball & basketball. The PSB Thumb Brace will increase joint stability at the base of the thumb after ligament damage & the tapes will protect against over extension & further jarring. This support will not inhibit wrist action & will allow full freedom of movement providing a comfortable option to guard against sports injury: For the prevention & protection against all thumb injuries. Skiers Thumb & Thumb Arthritis Suitable for thumb ligament injuries & following surgery. The PSB Thumb Brace is not suitable for tendonitis, tenosynovitis for (De Quervains) or rheumatism. What size do I need? The measurement should be taken around the middle of the h&. If you are between sizes, please choose the larger size. Small: 16-19 cm Medium: 19-22 cm Large: 22-25 cm